Electrical switch assembly

ABSTRACT

A CARBURETOR BODY HAS A PROJECTING BOSS FORMED THEREON WITH AN APERTURE FORMED THERETHROUGH INCLUDING A SLOT EXTENDING AXIALLY THEREOF THE FULL LENGTH OF THE APERTURE, AND AN INSULATING BODY HAVING A TUBULAR EXTENSION IS ASSEMBLED TO THE BOSS BY INSERTING THE TUBULAR EXTENSION THROUGH THE BOSS APERTURE, AND A GENERALLY CYLINDRICAL CONTACT AND THROTTLE STOP MEMBER IS ASSEMBLED THERETO BY INSERTING THE BODY OF THE CONTACT MEMBER THROUGH THE TUBULAR EXTENSION UNTIL COOPERATING ETENT-LIKE LOCKING MEANS ARE ENGAGING CAUSING THE CONTACT MEMBER, AND INSULATING BODY TO BE LOCKED TO THE BOSS.

Nov 2, 1971 R. F. scmn 3,616,781

ELECTRICAL SWITCH ASSEMBLY Filed Sept. 16, 1969 INVI'IN'I'UR.

I @oen Z Sabin! United States Patent 3,616,781 ELECTRICAL SWITCH ASSEMBLY Robert F. Sciotti, Warren, Mich., assignor to Holley Carburetor Company, Warren, Mich. Filed Sept. 16, 1969, Ser. No. 858,360 Int. Cl. F02p /04; F02m N08 US. Cl. 123-119 F 1 Claim ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Generally, it has been discovered to be beneficial, with respect to internal combustion engines employing an ignition distributor assembly and a carburetor, to provide means for causing a maximum retard condition of the ignition distributor assembly during curb-idle engine operation which, of course, is achieved when the throttle valve is permitted to assume its nominally closed position as would occur, for example, with the vehicle at rest and the engine merely idling.

It has now been discovered that such maximum retard systems can be energized and de-energized in response to the closing and opening of an electrical switch assembly and that it is best to provide, in such a system, an electrical switch wherein one of the contacts would be moveable along with the throttle valve or linkage associated therewith. To this extent is has also now been discovered that for various reasons it is beneficial to, in effect, provide such an electrical switch assembly secured to or carried by the carburetor structure. However, certain porblems have existed with respect to the provision of such an electrical switch assembly carried by a carburetor. The most difiicult of these problems being that quite often carburetor adjustments are necessary which in turn require the disengagement of the electrical switch assembly from the carburetor. Because of space limitations within the vehicular engine compartment it often becomes a major problem to employ any tools for disengaging mechanical fasteners which may be employed for retaining the switch assembly onto the carburetor.

Further, new functional requirements necessitate additional components to be added to the carburetor, which is already fitted with numerous components required to meet prior functional requirements. Therefore, it is desirable, in order to reduce complictaion and cost, to provide components that serve multiple purposes.

Accordingly, the invention as herein disclosed and claimed directs itself to the solution of the above as well as other problems.

SUMMARY OF THE INVENTION According to the invention, an electrical switch assembly comprises a mounting body, a passageway formed through said mounting body, an end of said body to said passageway, an electrical insulator, a generally tubular extension caried by said insulator and being received within said passageway, and an electrically conductive contact member received within said tubular extension and 3,616,781 Patented Nov. 2, 1971 "ice being effective to confine said tubular extension within said passageway, said contact member being effective to complete an electrical circuit therethrough upon being engaged by a moveable electrical contact associated therewith.

Accordingly, a general object of this invention is to provide a switch as set forth above wherein the various elements comprising the switch assembly can be quickly and easily disassembled if the need should arise.

Another object of the invention is to provide a switch assembly as generally set forth above wherein the mounting body is carried by a carburetor for an internal combustion engine.

A further object of the invention is to provide a switch assembly as set forth above wherein the first named electrical contact also serves as the usual abutment or stop member for linkage associated with the throttle valve of a carburetor structure.

Other more specific objects and advantages of the invention will become apparent when reference is made to the following detailed description considered in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS In the drawings, wherein, for purposes of clarity, certain elements and details may be omitted from one or more views:

FIG. 1 is a fragmentary side elevational view of a carburetor structure employing the teachings of the invention;

FIG. 2 is a fragmentary front elevational view of the structure shown in FIG. 1;

FIG. 3 is an enlarged fragmentary cross-sectional view taken generally on the plane of line 33 of FIG. 1 and looking in the direction of the arrows;

FIG. 4 is a fragmentary view taken generally on the plane of line 44 of FIG. 3 with portions of selected elements being broken away and in cross-section; and

FIG. 5 is a generally exploded perspective view of selected elements also shown in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now in greater detail to the drawings, FIGS. 1 and 2 illustrate a carburetor 10 having a body 12 with the usual air induction passage, fragmentarily shown at 14, formed therethrough having a suitable choke valve (not shown) for at times restricting the flow of air to the inlet end of the induction passage and a throttle valve 16 for controlling the flow of motive fluid from the induction passage to the intake manifold of the associated engine.

A choke shaft 18, extending transversely through the carburetor 10 and carrying the choke valve, has a lever 20 fixedly secured thereto as by a nut 22 engaged with a threaded portion 24 formed on the choke shaft 18. The other end of lever arm 20 has an aperture 26 formed therein which pivotally receives therethrough one end 28 of a connecting link 30 the other end 32 of which is slidably received within an arcuate slot 34 of a fast idle cam 36. The body of the fast idle cam 36 also includes a plurality of steps 38, 40, 42 and 44 formed on the periphery thereof so as to be adapted to at times be selectively abuttably engaged by end 46 of a fast idle stop screw 48 threadably engaged with and carried by a transverse arm portion 50 of a throttle lever 52. The fast idle cam 36 is secured to the carburetor body 12 as by a pivot member 54 while the throttle lever 52 is operatively connected to the throttle valve 16 by means of being fixedly secured to end 56 of a rotatable throttle shaft 58 which carries throttle valve 16.

As best shown in FIG. 2, throttle lever 52 can be seen to be comprised of generally upwardly directed legs 60 and 62 which are joined by a lower bight portion 64, leg 62 of lever 52 carries arm 50 while leg 60, at its upper end, is provided with an aperture 66 formed therethrough for the reception therein of suitable linkage operatively connected to the vehicle operators foot throttle control. In normal operation, clockwise rotation of lever 52 causes further opening of throttle valve 16 and, of course, causes the arm 50 and fast idle stop screw 48 to be correspondingly rotated clockwise about the centerline of throttle shaft 58.

The carburetor -10, as illustrated in FIGS. 1 and 2, is shown with the elements thereof in positions corresponding to a fully opened choke and curb idle. If the carburetor sensed that the engine was cold, the choke valve would be in its closed position causing lever 20 to have been rotated clockwise about the centerline of choke shaft 18 to some extreme position causing linkage 30 to be moved generally upwardly in accordance therewith. Such motion of linkage 30, in turn, through linkage end 32, causes fast idle cam 36 to be rotated counter-clockwise about pivot 54 until cam step 38 is brought generally into juxtaposition with end 46 of fast idle stop screw 48. If during this time throttle valve 16 was held in an opened position and now permitted to return towards its cloud or curb idle position, lever 52 and arm 50 would rotate counter-clockwise until end 46 of screw 48 abutted against cam step 3 8. when engagement between screw 48 and step 38 occurs, further movement of throttle valve 16 is precluded. However, as the engine becomes progressively warmer and the choke valve is correspondingly moved further toward its wide open position, lever 20 is progressively rotated counter-clockwise permitting downward movement of linkage 30 and downward or clockwise movement of fast idle cam 36 by its own weight, sequentially placing steps 40, 42 and 44 in juxtaposition with fast idle stop screw 48. Obviously, it can be seen that as the occasion arises for stop screw 48 to engage first step 40, then 42 and finally step 44, that each such engagement permits the throttle valve :16 to more nearly approach its nominally closed or curb idle condition.

Finally, when choke valve and shaft 18 have been rotated to the fully opened choke condition, linkage 30 and cam 36 have both experienced sufiicient downward movement as to, generally depicted in FIG. 1, preclude further engagement between the fast idle stop screw 48 and cam 36 when throttle valve 16 is rotated toward its curb idle position. At this time, that being with the choke valve fully opened, the curb idle position of the throttle valve is determined by a throttle stop screw 68, which is threadably engaged with and carried by arm 50, engaging suitable abutment means 70.

Before progressing with the description of the abutment means 70, it should be noted that FIG. 1 also somewhat schematically illustrates an ignition system distributor assembly 72 provided with suitable spark advance and re tard mechanism including a lever 74 operatively connected to solenoid means 76. As shown, one end of the solenoid winding 77 or coil is connected via suitable circuit means to a source of electrical potential 78 which may be grounded as at 80, While the other end of winding 77 is connected to electrical conductor 82.

FIG. 3, an enlarged fragmentary cross-sectional view taken generally on the plane of line 3--3 of FIG. 1, illustrates in greater detail the abutment means 70 which, as will become evident, performs a plurality of important functions. As shown in FIGS. 1, 2 and 3, the carburetor body 12 is preferably provided with a projecting arm-like boss 84,'preferably formed integrally therewith, which has an aperture or passageway 86 formed therethrough. As also shown in both FIGS. 4 and 5, a slot 88 is also formed in boss 84 so as to break through aperture 86 and thereby form an access means to the aperture 86.

4 As can be seen in FIG. 3, the slot 88 is the full width of boss 84.

In assembled condition, as shown in FIG. 3, a generally tubular projection 90 of an insulating member 92 is received through aperture 86 and, in turn, receives a stop member 94 therethrough which also serves as a fixed electrical contact. A cavity or aperture 96 formed in the main body portion 98 of stop-contact 94 serves to receive a plug type electrical terminal 100 which is connected to one end of electrical conductor 82. Preferably, plugv or terminal 100 is soldered within cavity 96; however; it could also be connected thereto by any means conforming to good practice in the art of electrical circuitry. The other end of conductor 82 may carry a rather, in comparison, large electrical connector 102 for completing electrical connection with, for example, a terminal of the solenoid winding 77.

As also shown in FIG. 5, the electrically insulating member 92 includes a first wall portion 104 the inner surface of which is adapted to abuttably engage the frontal surface or face 106 of boss 84, and a second wall portion 108, joined to wall 104, adapted to be in close proximity to the projecting end surface 110 of boss 84. The tubular projection 90 is preferably slotted or relieved as at 112 so as to permit a somewhat radial collapse of the tubular projection 90 when it is inserted into aperture 86. Such a radial squeezing is made necessary in order to accommodate the annular ridge or abutment portion 114 formed on the outer surface of tubular projection 90. As shown in both FIGS. 3 and 5, the end of tubular projection 90 is provided with a radially inwardly directed annular flange 116 which is adapted to engage and become seated within a cooperating annular groove 118 formed in the outer diameter 120 of stop-contact body 9 8.

In order to best illustrate the operation and features of the invention, let it be assumed that the connector 102 is substantially larger than the aperture 86 in boss 84 and that the connector 100 is to be soldered into cavity or aperture 96. With the above assumption the procedure for assembling the abutment means 70 is as follows. First, plug terminal 100 is drawn through aperture or passage- 'way 122, formed through wall 104 and tubular projection 90, and then received in and soldered within the cavity 9 6 of stop-contact 94 thereby having the contact 94 assume a position relative to insulator member 92 as generally depicted in FIG. 5. Next, that section of conductor 82 extending out of the end of projection 90 is passed, generally sideways, through slot 88 so as to be received within and through boss aperture 86. At this time the conductor 82 is extending through aperture 86 and the tubular projection '90 with the insulator member 92 and stop-contact 84 being disposed on the generally forward side of boss 84 while the connector 102 is connected to conductor 82 and disposed on the opposite or rearward side of boss 84.

Next, the insulator '92 is moved so as to insert tubular projection 90 into aperture 86. As tubular projection 90 is thusly pushed through aperture 86, the abutment ring 114 engages the surface of aperture 86 causing the tubular projection 90 to radially deflect an amount sufficient to permit such abutment ring 114 to pass through the aperture 86. At about the time that wall 104 engages face 106 of boss 84 the abutment portion or ring exits from the rear of aperture '86 and the general resiliency of the material forming the tubular portion 90 causes the annular ridge 114 to move generally radially outwardly so as to in effect engage the rearward surface 124 of boss 84, as shown in FIG. 3.

With the insulator 92 thusly seated, the stop-contact 94 is then pushed through aperture or passageway 122 formed in insulator 92. The outer diameter 120 of body portion 98 and the inner diameter or aperture 86 are such as to permit the wall thickness of the tubular extension 90 to be closely confined therebetween. Accordingly, main body portion 98 of contact member 94, as

it is being pushed through aperture or passageway 122, continually forces or assures the radial outward displacement of the tubular projection 90. The insertion of contact member 94 continues until head portion 126 engages forward wall 104 at which time the radially inwardly directed flange portion 118, which was previously resiliently deflected radially outwardly by the leading portion of the main body 98, comes into juxtaposition with annular groove 118 and becomes seated therein as shown in FIG. 3.

At this time the assembly 70 becomes locked and the stop-contact 94 provides a dual function. That is, once the fast idle cam 36 and the fast idle stop screw 48 cease to function as a means for determining the degree of permissible throttle closure, head portion 126 of stop member 94 serves as the abutment or stop for the throttle stop screw 68 during normal temperature operation of the carburetor. It will be further noted that screw 68 engages member 94 in a direction to maintain the assembly 70 in the assembled condition, its inadvertent disassembly, as might otherwise occur.

In addition to the above, stop member 94 being of electrically conductive material serves as a fixed electrical contact which when engaged by the electrically conductive throttle stop screw 68, completes the electrical circuit through conductor 82, as generally shown in FIG. 1, energizing the solenoid 76 and causing a retard in the timing of the ignition distributor assembly 72. Although not shown, it should be apparent that the closure of the switch assembly, comprised of contact 94 and screw 68, could be employed for causing actuation of an associated relay which, in turn, caused energization of the solenoid means 76.

Additionally, wall 108 of member 92 provides a rubbing block for link 30, preventing its inadvertent removal from the slot 34 in cam 36.

In the event that carburetor repairs should become necessary, it is of course possible to easily disengage the assembly 70 therefrom by merely reversing the procedure previously described. That is, first the locklng flange portion 116 is forced outwardly from groove 118 and the contact 94 is pushed out of passageway 122; next, the insulator 92 and the tubular projection 90 are withdrawn from aperture 86 in boss 84 and finally the conductor 82 is slipped sideways out of aperture '86 through slot 88 thereby freeing the entire contact assembly from the carburetor 10.

In addition to the above, the invention provides other benefits. For example, as previously stated, when assembled as shown in each of FIGS. 1, 2, 3 and 4, side wall 108 of insulator 92 is positioned as to have its outermost surface 128 closely spaced to the linkage 30 interconnecting lever 20 and fast idle cam 36. The benefits of this arrangement will be better appreciated when one considers the prior art structures and the manner employed therein for securing the linkage 30 to the fast idle cam. For example, it has been accepted practice to provide linkages such as 30 for the purpose described; however, such prior art linkages had their transverse end portions as 32 formed as to project through and a substantial distance beyond the slot, such as 34, formed in the fast idle cam 36. Such projecting portion of end 32 was then formed to have an annular groove formed thereabout which, in turn, received a retainer therein, such as a C-type snap ring, for preventing the unintentional withdrawal of linkage end 32 from the cooperating slot 34.

However, the invention eliminates the necessity of providing such a separate retainer or snap ring as well as the necessity of forming the annular groove for the reception of such a retainer. The invention, by providing the wall 108 in close proximity to linkage 30 serves to limit movement of the linkage 30 so as to prevent withdrawal of end 32 out of slot 34. This, of course, is accomplished without the need of having to perform any additional manufacturing operations on the linkage 30 (as for the formation of the annular retainer groove) or the assembly of additional retaining means onto the end 32 of the linkage 30.

Although only one preferred embodiment of the invention has been disclosed and described, it is apparent that the other embodiments and modifications of the invention are possible within the scope of the appended claim.

I claim:

1. A carburetor having an electrical switch assembly, said carburetor comprising an induction passage, a shaftmounted throttle valve in said induction passage, a shaftmounted chock valve in said induction passage upstream of the said throttle valve, a fast idle cam pivotally mounted on said carburetor between said throttle valve and said chock valve, said fast idle cam being formed with an arcuate slot, linkage between said choke valve and said fast idle cam with one end of said linkage having a lateral portion positioned in said slot, a throttle operating lever fixedly secured to said throttle shaft, an adjustable abutment member on said throttle lever for setting the idle position of said throttle valve, said electrical switch assembly comprising a boss formed on said carburetor and extending toward said linkage, said boss having an aperture therethrough and a slot extending from said aperture to the outer end of said boss, an insulator member having walls adapted to engage one side and said outer end of said boss and a tubular extension position in said aperture in said boss said tubular extension being formed with means allowing it to be yieldingly inserted through said aperture, an external flange on said extension engaging the opposite side of said boss to prevent is inadvertent removal and an inwardly extending flange at the free end thereof, a conducting member having an enlarged head at one end and a tubular portion positioneed within the tubular portion of said insulating member, said tubular portion having external recess on the other end thereof, said tubular portion preventing inward yield of said tubular extension of said insulating member and receiving the inwardly extending flange of said insulating member, an electrical conductor including a connector fitted within said tubular portion of said conducting member, the above recited structure of said switch assembly being such that it is easily assembled by inserting the terminal end of said conductor through said tubular extension of said insulating member and into said tubular portion of said conducting member, inserting said conductor through said slot and into said aperture of said boss, snapping said insulator extension into said aperture and snapping said tubular portion of said conducting member through the tubular extension of said insulating member to lock said assembly, said enlarged head of said conducting member cooperating with said abutment member on said throttle lever to set the idle position of said throttle valve, the wall portion of said insulator member engaging the free end of said boss being disposed sufficiently closely adjacent said linkage to prevent the inadvertent disengagement of said linkage from said slot.

References Cited UNITED STATES PATENTS 1,882,720 10/1932 Arthur 123-117 2,042,616 6/1936 McCollum 123--117 X 3,180,576 4/1965 Herman 123--119 3,248,096 4/1966 Ball 1231l9 WENDELL E. BURNS, Primary Examiner US. Cl. X.R. 123-1l7 

